Automatic firearm.



PATENTED DEC. 31, 1907.

C. L. H. PRINKE. AUTOMATIC FIREARM. APPLIOATIQN FILED MAR. 28, 1907.

2 SHEETS-SHEET 1.

x i A No. 875,209. PATENTED DEG. 31, 1907.

0. L. H. PRINKE: AUTOMATIC FIREARM.

A-PPLIOATION FILED MAR. 28, 1907.

2 SHEETS-SHEET 2.

CARL L. H. PRINKF, OF

BALTIMORE, MARYLAND.

AUTOMATIC FIREARM.

Specification of Letters Patent. 3 Application filed March 28,1907. Serial No. 36%954- in the city of Baltimore and State of Mary land, United States of America, have invented certain new and-useful Improvements in Automatic Firearms, of which the following is a specification. v

This invention-relates to that class of firearms in which the force of the expanding gases developed immediately after firing is employed to open the breech, extract and eject the shell, cock the arm and permit the feed of a fresh cartridge. In such arms a fresh load is usually inserted by the breech bolt which immediately moves forward after recoil and the cartridge is exploded by a firing pin carried by and moving independently of the breech bolt.

By my improvements, when the breech bolt moves rearwards after firing, it is'cocked in its retracted position and a cartridge is autoinatically fed from the magazine into the path of the bolt. No independently movable firing pin is used but the breech bolt carries a fixed firing point or spur. When the bolt is unlocked, it moves forward, inserts a cartridge in the cartridge chamber of the barrel and simultaneously fires it. The shell is blown out into the receiver by the explosion gases and it is expelled from the receiver by an ejector carried by the bolt.

My invention involves certain improvements in the mechanism for simultaneously loading and firing, in the trigger or locking mechanism for the bolt, in the magazine or cartridge feed box and in the means for looking the barrel and receiver to the forearm of the piece.

In the accompanying drawings: Figure 1 shows a vertical central section of the breech portion of an automatic fire arm embodying my improvements, some of the interior parts being shown in elevation and these parts being shown in the positions they assume at the moment of firing. Fig. 2 is a similar, view l a side elevation of the follower. Fig. 5 shows a vertical section thro ugh the rear portion of the magazine. Fig. 6 shows a side elevation of the arm with part of the barrel and butt stock broken away Figs. 7 and 8 .show'the receiver and barrel separated from the framecarryjing the magazine and trigger mechanism. ig. 9 is a bottom plan view of the partp shown-1n Fig. 7. Fig. 9 is a front view of the firing bolt. Fig 10 is a top plan view of the parts shown in ig. 8. Fig. 11 is a detail view of the breech end of the barrel and Fig. 12shows a vertical section-on the line 1212 of Fig. I1.

the bare], a, by a threaded joint and it is provided with a threaded socket, b, to receive the assembling screw, h. The frame, 0, has the usual shank, g, connecting it with the butt stock, (1, and a recess, 0 to receive the boss, b, in which the socket, 12 is located andit has a lug, 0 formed with a flat top and which enters a recess, 0 in the rear end of the forearm. The barrel, (1, has a flattened part, a just in front of its threaded portion with which the to of the lug, 0 engages when the parts are ocked together.

The parts are secured together by means of the assembling screw, 77., in themanner indicated, that is to say, the assembling screw extends vertically through the front portion of the frame, 0, and en ages the socket, b of the receiver. When t e'parts are thus assembled the top ofthe. lug, c bears. against the flat portion, (1?, ofithe barrel and revents it from turning and the lug, c and t at art of the frame, c,"be low the lug is held tig tly in its socket, c A screw, T, is employed to attach the barrel to the forearm, e, in the usual way. The barrel can be detached from the receiver when they are removed fromthe frame by merely loosening the assembling screw and when the barrel is removed the front end of the receiver is fully opened so that the firing bolt and other working parts associated therewith can be removed through the front of the receiver, thus enabling me to have a solid or integral rear end for the receiver. R will be observed that-the shock of recoil is not taken by the assembling screw but by the frame as the boss I) fits the recess, 0 in the frame closely and relieves the screw from the shock orstrain of recoil. A shoulder, b, is formed near the'rear end of the receiver andin rear of this shoulder is a socket, b", for a purpose PatenteiiDec. 31,1907.

' The tubular receiver, 6, is connected with ioe hereinafter described. The breech bolt, or as 1 call it, the firing bolt, A, is mounted to slide back and forth in the receiver in line with the barrel and it carries at its front end a fixed firing spur, pin or projection, A, located below its axis. The firing bolt is hollow, being formed with three chambers, A, A A, of different diameters,- the latter chamber being made to extend through the front end of the firing bolt. An action spring or firing spring, K, has its front end arranged in the rear chamber, A, of the firing bolt and it extends back into the socket, b in which is also arranged the action spring guide, B, carrying on its front end an ejector operating pin, B. The head, I), of the guide, is pressed at all times fn'mly against the rear wall of the socket, b and the action s ring tends to move the firing bolt towar the breech of the barrel.

D indicates an ejector which is guided in the chamber, A and extends through the chamber, A. When operating to eject a shell, it rejects beyond the front end of the firing bo t, but isat other times retracted by a relatively light s ring, L, which is interposed between the front wall of the chamber, A and the head, d, of the ejector. The head of the ejector bears against the front coil of the action spring which holds it normally in the position shown in Fig. 1, where the relative positions of the firing bolt and the ejector are shown as they appear at the moment of firing, while in Fig. 2 they are shown in the positions they assume soon' after firing, i. e., after recoil,'where it will be observed that the springs, K and L, are compressed and the ejector protrudes from the iront oi the firing bolt.

it will be observed that the bolt is advanced by the combined pressures of both springs, K and L, and that both springs serve to brake the recoil. By causing the front coil of the spring, K, to bear against the rear end of the ejector when the breech is closed the ejector is revented from falling out should the gun be lield in a vertical position with its butt stock lowermost. The front end of the ejector is arranged a little to one side of the axis of the bolt so as to strike the rear end of the shell at one side of its axis.

the manner here after described. On its under side, the firing bolt is formed with a shoulder, b with which the sear, E, engages, and it is formed also on its under side near the front of the recess, 12 to permit it to pass over the top of the magazine, H. A side 0 ening, X, is formed in the receiver through w hich extends a handle, Z, which projects laterally from one side of the firing bolt and by means of which the bolt may be retracted by hand, if desired. This handle serves to prevent the bolt from turning and serves also to retain the bolt in the receiver when This causes the shell to be ejected in the arm is taken apart. By detaching the handle from the firing bolt, the latter may be easilyremoved from the receiver.

The magazine or cartridge box, II, is closed at the bottom and on all sides, but is open at the top. lts sides, which are of sheet metal, are grooved. to form corresponding vertical ribs, 11", in the front portion of the box which serve to hold the front ends of the cartridge in line one above the other. The rear portionof the box is suiliciently wide to allow of the cartridges being staggered in the manner illustrated in Fig. 5". At the top of the magazine an overhanging, forwardly projecting lip, ll, is formed on the rear wall and just in front of this lip on opposite sides, lips, H, are formed which prevent the rear end of the top cartridge from rising out of the magazine until it has been moved forward by the firing bolt.

The upper edge of the-front wall of the magazine 1s beveled or inclined at h, for the purpose of elevating the front end of the top cartridge to facilitate its passage to the cartridge chamber, a, which is flared as shown for a similar purpose. The forwardly rojecting, lip, H, cooperates with the inclined surface, h, in the following way. As the topmost cartridge in the magazine rises after the recoil of the firing bolt, it is held by the lip a little in advance of the others below it with its front end above the inclined surface, 2., so that the tendency of the front end of the cartridge to lower into the magazine is prevented. The front end of the cartridge under such circumstances will be received b the inclined surface and as the firing bot moves forward the front end of the cartridge will rise on the incline and enter the barrel. WVere it not for this the front end of the cartridge might be depressed to such an extent in the magazine as to become caught in the front wall thereof. The magazine or box, H,- is detachably connected with the frame of the arm by means of a spring catch, G,

ivoted near its middle portion at t and havmg a tooth, G, above its pivot arranged to engage either of two recesses, 9, 9*, in the rear wall of the box. VV'hen the tooth engages the notch, g, the magazine is held below itsfeeding position, but when the tooth engages the notch, g the magazine is held in feeding position and will automatically feed cartridges to the receiver and hold them in osition to be carried to the cartridge chamlier of the barrel by the firing bolt.

The magazine spring, 0, is of usual construction and operates in conjunction with a follower, P, which is formed at its rear end with an upwardly rojecting rearwardly i11- clined arm, P, an at its front end with a downwardl projecting rearwardly inclined arm, P he arms, P and P are arranged to bear against the rear and front walls respectively of'the magazine. The rear end of the bottom cartridge in the magazine lies against the front 0 the arm P, and this arm, after the last cartridge is fed, strikes the overhanging lip, H, at the top of the magazine. The arm, P prevents the follower from being ejected from the magazine after the last cartridge has been fed; It will be understood that the rear end of the follower cannot leave the magazine by reason of its engagement with the lips, H and H but there are no correspondmg lips at the front end of the magazine and the follower tends to rise therefrom but in doing so it swings about an axis coincident with the rear ortion of the follower and the arm, P strikes and binds against the front wall of the magazine and is thus prevented from rising to any great extent.

The sear, E, is pivoted to the frame at n, and its u per rear end operates through an opening, 81$, in the bottom of the receiver and engages at times the shoulder, 12 of the firing bolt. The sear spring, M, engages the catch, G, above its pivot, t, and therefore serves the double purpose of pressing the sear into engagement with the firing bolt and holding the catch in engagement with the magazine. It will be observed that the lower end of the catch, G, is within the trigger guard, f, inconvenient position for being operated by the trigger finger, which, in releasing the catch, moves forward. A stop,

f, limits the rearward movement of the lower end of the catch. The trigger, F, is pivoted to the frame at 1', below the sear and it carries a spring pawl, I, pivoted to the trigger at s, and adapted to engage a lug, i, on the lower front side of the sear below its pivot. A spring, N, interposed between the trigger and the front end of the pawl tends to cause such engagement. When the parts are in the position shown in Fig. 1, the arm is ready to be cooked. When the firing bolt moves rearwards, the sear is depressed in the usual way and then engages the shoulder, b but in the arrangement shown, the pawl, I, does not immediately enter behind the lug, '11. It is first necessary to press against the front end, F, of the trigger. This causes the pawl to engage behind thelug, '2, and the arm is then cocked, set andready for firing and the parts will appear as illustrated in Fig. 2. When the trigger is pulled, the sear is swung on its pivot, re easing the firing bolt and the pawl, 1, moves from behind the lug, i, of the sear and the parts assume the position shown in Fig. 1. By this arrangement it will be observed that the firing bolt may move back to its cocked position while the trigger finger is still on the trigger and while the sear engages the firingbolt and cooks it, the arm is not in firing condition until after the trigger is moved a short distance forward. g

It will be observed that the arm is en I tirely automatic, it being necessary only to operate the trigger to fire the entire charge o cartridges in the magazine. When the arm is in firing condition, as indicated in Fi 2, and the tri ger is pulled, the firing b0 t moves forward, the point A", engages the upper, rear end of the top cartridge, m, in the magazine, first shoves it against the incline, h, and then into the cartridge chamber, a. 1 It will be observed that the lip, H,

forward before it is struck by the bolt and that the oint, A, operates just above the lip. As t e bolt moves forward after engaging the cartridge, the latter centers itself into line with the axis of the barrel, its rear end sliding up across the face of the .pin. Immediately after the cartridge is thus inserted, it-is fired by the further advance of the bolt. The force of the ases developed by the explosion causes the ring boltto retract to its cocked position and it is imme diately engaged by thesear while the shell is also at the same time extracted or is driven into the receiver chamber and the ejector, D, advances from the front of the firing bolt, strikes the shell and expels it through the opening, X, at the side of the receiver. A cartridge then rises to the top of the magazine into position in front of the lip, H, to be engaged by the firing bolt on its next for-. ward movement. After firing and cocking in the manner described, the pawl, I, is set arm may be again fired and the operation before described will be repeated.

Inasmuch as there are no parts projecting from the rear end of the receiver, I have attached thereto a vertically adjustable sight, Q, which has a peep hole, q, and a top notch, (1". The sight, Q, is in the form of a plate having a slot, Q, through which extends a clamping screw, Q engaging the rear end of the receiver. 7

It will be observed that the firing bolt does not move back fully to the rear end of the receiver but is arrested by the shoulder, I), thus permitting me to use more metal at the rear end of the receiver to receive the shock of recoil. V

The arm may conveniently be used as a single loader, the cartridges being inserted through the opening, X.

The arm is easily cleaned as there are but few arts, and these are l'argelyloose and readi y detached. The firing bolt, the'action spring, the action spring guide, the ejector, its spring, the sear spring, and the pawl spring, N, are all loose and can be readily taken out and cleaned. The barrel can be detached from thereceiver and the firing bolt and parts associated therewith canall be easily withdrawn through the front end of the receiver. This is done by detachingthe .magazine, loosening the ascauses the top cartridge to move slightly by moving the trigger forwards and then the sembling screw and then unscrewing the barrel.

I claim as my invention:

1. An automatic firearm, comprising a receiver, a magazine for automatically feeding cartridges thereto, a firing bolt adapted to engage a cartridge in the receiver on its forward movement to feed it to the cartridge chamber of the barrel and to fire it and which bolt is provided with a sprin for advancing it but which is free to recoil, r the pressure of gases developed immediateiy after firing, an ejector carried by but movable independently of the firing bolt, means for automatically cocking the bolt on its recoil and de-- vices for releasing the bolt.

2. An automatic firearm, comprising a receiver, a firing bolt therein, a spring tending to move the firing bolt forwards, a firing anism for cocking and releasing t point fixed to the firing bolt, trigger moch- I e bolt, an ejector carried by the firing bolt, means for withdrawing the ejector into the bolt as the latter moves forward and means for projecting the ejector'from the front end of the firingbolt when the latter reaches the limit of its rearward movement.

' 3. An automatic firearm, comprising a receiver, a' magazine connected therewith and feeding thereto, a firin bolt reciprocatin in the receiver having a ing point adapted to engage the topmostv cartridge in the magazine and feed it to the barrel on its forward movement and to simultaneously fire it, an ejector carried by and movable independently of the firing bolt, a scar for automatically cooking the bolt when it reaches the limit of its rearward movement, and trigger mechanism for releasing the sear.

4. The combination of a receiver, a firing bolt reciprocating therein, a spring tending to move'the bolt forwards, an e ector mounted eccentrically within the bolt and adapted to rotrude from the front end thereof, a spring. for retracting the ejector when the bolt is in its forward position, and. means for causi the ejector to protrude from the bolt when t e latter reaches its retracted position.

5. The combination with the 'barrel of a tubular receiver detachably connected therewith and having a solid or integral rear end provided with a shoulder near its rear end and a socket in the rear of said shoulder, a reci rocating firing bolt of less diameter than t e front end of the receiver, an action spring engaging the firing bolt and having its rear end arranged in said socket at the rear end of the receiver, and anaction spring guide loosely arranged within the receiver having its rear end 1n said socket, said bolt, s ring and guide being removable through the front end. of the receiver when the latter is detached from the barrel. 1

6. The combination of a tubular receiver,

ally by the bolt at its front end above the plane of the firing-point, a spring tending to move the ejector rearwards relatively to the firing bolt, an action spring engaging the receiver at its rear end and pressing against the rear end of the ejector when the e ector is in its rearmost position and means for moving the. ejector forward and compressing its spring when the firing bolt reco1ls,-the arrangement being such that both the action s ring and the ejector spring serve to brake t e recoil of the firing bolt.

7. The combination of a barrel, a receiver in rear thereof, a firing bolt in the receiver reciprocating in line with the barrel, means for cocking the bolt, a trigger for firing the arm anda magazine cartridge box arranged in front of the trigger containing a sprin pressed follower and com rising vertical si e walls formed with inwardly pro ecting lips at the top for limiting the u ward movement of the cartridges, a vertica front wall formed with an inclined 11 per edge arranged close to and leading directiy to the cartridge chamber of the barrel and a rear wall formed with a forwardly projecting lip which as the cartridges rise in the box causes the topmost cartrid c to move forward and assume a 1jiggition in ine with the lower portion of the bolt with its front end above but close to the inclined surface on the front wall of the box.

8. Thecombination of the barrel, the receiver, a magazine having a beveled or inclined front wall at the top, an inturned tolp lip at the rear, and a reciprocating firing bo carrying a forwardly ro'ecting below its axial line w 'ch most cartridge in the magazine, feeds it to the barrel and fires it.

9. The combination of the receiver, the barrel having a threaded connection therewith, a boss on the receiver having a threaded socket for the assembling screw, the frame provided with a recess to receive the boss on the receiver, and an assembling screw for connecting the parts.

10. The combination of the receiver having an integral rear end, the barrel. having a threaded connection with the receiver, the firing bolt removable through the front end of the receiver when the barrel is detached, 8. boss on the receiver having a threaded socket for the assembling screw, the frame provided with a recess to receive the boss and an assembling screw for connecting the parts.

11. The combination of the receiver, the barrel-having a threaded connection therewith, a boss on the receiver having a threaded socket for the assembling screw, the forearm having a vertical socket at itsrear end, theframe provided with a recess to receive ring point engages the topthe boss on the receiver and formed with a lug entering the socket in the forearm and an assembling screw for connecting the parts.

12. The combination of the receiver and the barrel having a threaded connection therewith and provided with a flat surface in advance of its threaded portion, a boss on the receiver having a threaded socket for the assembling screw, the forearm having a vertical socket at its rear end, the frame provided with a recess to receive the boss on the receiver and formed with a lug entering the socket in the forearm and having a flat top surface engaging the flattened surface of the barrel and an assembling screw for connect- 15 ing the parts.

In testimony whereof, I have hereunto subscribed my name.

' CARL L. H. PRINKE. Witnesses:

SAMUEL J. FIsHER, ALLAN HERBERT FISHER. 

